Bayer Aktiengesellschaft

Fritz Doring

Gunther Beck

Gerhard Dankert

Herbert Schwarz

Josef Heinrich

Hans Holtschmidt

Erich Klauke

Hermann Hagemann

Reinhold Gehring

Helmut Heitzer

Gerhard Buttner

Karl-Erwin Schnalke

Nuclear-halogenated benzotrichlorides are prepared in a particularly advantageous manner from the corresponding nuclear-halogenated benzotrifluorides by reacting nuclear-halogenated benzotrifluorides with silicon tetrachloride in the presence of catalytic amounts of aluminium trichloride.

Process for the preparation of nuclear-halogenated benzotrichlorides

A novel process for the preparation of benzodioxoles of the formula (I) ##STR1## in which Hal represents a chlorine atom or a fluorine atom, from dichlorobenzodioxole using stoichiometric quantities of anhydrous hydrofluoric acid.

Process for the preparation of difluorobenzodioxole and

2,4,5-Trichloropyrimidine is obtained by reacting 2-cyanoethyl isocyanide dichloride with hydrogen chloride and then reacting the product with chlorine.

Process for the preparation of 2,4,5-trichloropyrimidine

Process for the preparation of tetrachloropyrimidine, characterized in that 2-cyanoethyl isocyanide dichloride is reacted with chlorine in the gas phase in the temperature range from 200.degree.-650.degree. C.

2-Cyanoethyl isocyanide dichloride

Process for the preparation of tetrachloropyrimidine

A process for preparing a xylene which is fluorinated and chlorinated in the side chain, having the formula ##STR1## wherein X represents hydrogen or fluorine and

Preparation of trichloromethyl-trifluoro methyl-benzenes

A process for preparing tetrachloropyrimidine comprising reacting 2-cyano-1,2-(dichlorovinyl)-isocyanide-dichloride of the formula

Perchlorodiazafulvene having the formula ##STR1## IS PREPARED BY REACTING 2,4,5-TRICHLORO-2-TRICHLOROMETHYL-2H-imidazole having the formula ##STR2## WITH DECHLORINATING AGENTS AT ELEVATED TEMPERATURES AND IS USEFUL AS A FUNGICIDE.

Perchlorodiazafulvene

N-chlorocarbonyl isocyanide dichloride is prepared by chlorinating methyl isocyanate and/or methyl carbamic acid chloride in solution in the presence of ultraviolet light at a temperature in the range of from 30.degree. to 120.degree.C. The temperature pattern during the reaction is controlled in relation to the concentration of methyl isocyanate in the reaction mixture such that low temperatures are maintained for high concentrations while high temperatures are maintained with low concentrations. Thus, when a temperature of from 30.degree.-40.degree.C is maintained during the reaction, the concentration of methyl isocyanate in the reaction mixture is substantially more than 50 percent; when the temperature is increased to 65.degree. to 75.degree.C, the concentration of methyl isocyanate is in the range of 50 percent to 10 percent; and when the temperature is increased above 75.degree.C, the concentration of methyl isocyanate is substantially below 10 percent.

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Odenthal, Germany

Fritz Doring